System and method for treating the structure of the human lens with a laser

ABSTRACT

suture layer of the lens.

BACKGROUND OF THE INVENTION

The present invention relates to systems and methods for treating thestructure of the natural human crystalline lens with a laser to addressa variety of medical conditions such as presbyopia, refractive error andcataracts and combinations of these.

The anatomical structures of the eye are shown in general in FIG. 1,which is a cross sectional view of the eye. The sclera 131 is the whitetissue that surrounds the lens 103 except at the cornea 101. The cornea101 is the transparent tissue that comprises the exterior surface of theeye through which light first enters the eye. The iris 102 is a colored,contractible membrane that controls the amount of light entering the eyeby changing the size of the circular aperture at its center (the pupil).The ocular or natural crystalline lens 103, a more detailed picture ofwhich is shown in FIGS. 1A-F, (utilizing similar reference numbers forsimilar structures) is located just posterior to the iris 102. The termsocular lens, natural crystalline lens, natural lens, natural humancrystalline lens, and lens (when referring to the prior terms) are usedinterchangeably herein and refer to the same anatomical structure of thehuman eye.

Generally, the ocular lens changes shape through the action of theciliary muscle 108 to allow for focusing of a visual image. A neuralfeedback mechanism from the brain allows the ciliary muscle 108, actingthrough the attachment of the zonules 111, to change the shape of theocular lens. Generally, sight occurs when light enters the eye throughthe cornea 101 and pupil, then proceeds through the ocular lens 103through the vitreous 110 along the visual axis 104, strikes the retina105 at the back of the eye, forming an image at the macula 106 that istransferred by the optic nerve 107 to the brain. The space between thecornea 101 and the retina 105 is filled with a liquid called the aqueous117 in the anterior chamber 109 and the vitreous 110, a gel-like clearsubstance, in the chamber posterior to the lens 103.

FIG.1A illustrates, in general, components of and related to the lens103 for a typical 50-year old individual. The lens 103 is amulti-structural system. The lens 103 structure includes a cortex 113,and a nucleus 129, and a lens capsule 114. The capsule 114 is an outermembrane that region envelopes the other interior structures of thelens. The lens epithelium 123 forms at the lens equatorial 121generating ribbon-like cells or fibrils that grow anteriorly andposteriorly around the ocular lens. The nucleus 129 is formed fromsuccessive additions of the cortex 113 to the nuclear regions. Thecontinuum of layers in the lens, including the nucleus 129, can becharacterized into several layers, nuclei or nuclear regions. Theselayers include an embryonic nucleus 122, a fetal nucleus 130, both ofwhich develop in the womb, an infantile nucleus 124, which develops frombirth through four years for an average of about three years, anadolescent nucleus 126, which develops from about four years untilpuberty which averages about 12 years, and the adult nucleus 128, whichdevelops at about 18 years and beyond.

The embryonic nucleus 122 is about 0.5 mm in equatorial diameter (width)and 0.425 mm in Anterior-Posterior axis 104 (AP axis) diameter(thickness). The fetal nucleus 130 is about 6.0 mm in equatorialdiameter and 3.0 mm in AP axis 104 diameter. The infantile nucleus 124is about 7.2 mm in equatorial diameter and 3.6 mm in AP axis 104diameter. The adolescent nucleus 126 is about 9.0 mm in equatorialdiameter and 4.5 mm in AP axis 104 diameter. The adult nucleus 128 atabout age 36 is about 9.6 mm in equatorial diameter and 4.8 mm in APaxis 104 diameter. These are all average values for a typical adulthuman lens approximately age 50 in the accommodated state, ex vivo. Thusthis lens (nucleus and cortex) is about 9.8 mm in equatorial diameterand 4.9 mm in AP axis 104 diameter. Thus, the structure of the lens islayered or nested, with the oldest layers and oldest cells towards thecenter.

The lens is a biconvex shape as shown in FIGS. 1 and 1A. The anteriorand posterior sides of the lens have different curvatures and the cortexand the different nuclei in general follow those curvatures. Thus, thelens can be viewed as essentially a stratified structure that isasymmetrical along the equatorial axis and consisting of long crescentfiber cells arranged end to end to form essentially concentric or nestedshells. The ends of these cells align to form suture lines in thecentral and paracentral areas both anteriorly and posteriorly. The oldertissue in both the cortex and nucleus has reduced cellular function,having lost their cell nuclei and other organelles several months aftercell formation.

Compaction of the lens occurs with aging. The number of lens fibers thatgrow each year is relatively constant throughout life. However, the sizeof the lens does not become as large as expected from new fiber growth.The lens grows from birth through age 3, from 6 mm to 7.2 mm or 20%growth in only 3 years. Then the next approximate decade, growth is from7.2 mm to 9 mm or 25%; however, this is over a 3 times longer period of9 years. Over the next approximate 2 decades, from age 12 to age 36 thelens grows from 9 mm to 9.6 mm or 6.7% growth in 24 years, showing adramatically slowing observed growth rate, while we believe there is arelatively constant rate of fiber growth during this period. Finally, inthe last approximately 2 decades described, from age 36 to age 54, thelens grows by a tiny fraction of its youthful growth, from 9.6 to 9.8 mmor 2.1% in 18 years. Although there is a geometry effect of needing morelens fibers to fill larger outer shells, the size of the older lens isconsiderably smaller than predicted by fiber growth rate models, whichconsider geometry effects. Fiber compaction including nuclear fibercompaction is thought to explain these observations

In general, presbyopia is the loss of accommodative amplitude. Ingeneral refractive error is typically due to variations in the axiallength of the eye. Myopia is when the eye is too long resulting in thefocus falling in front of the retina. Hyperopia is when the eye is tooshort resulting in the focus falling behind the retina. In generally,cataracts are areas of opacification of the ocular lens which aresufficient to interfere with vision. Other conditions, for which thepresent invention is directed, include but are not limited to theopacification of the ocular lens.

Presbyopia most often presents as a near vision deficiency, theinability to read small print, especially in dim lighting after about40-45 years of age. Presbyopia, or the loss of accommodative amplitudewith age, relates to the eyes inability to change the shape of thenatural crystalline lens, which allows a person to change focus betweenfar and near, and occurs in essentially 100% of the population.Accommodative amplitude has been shown to decline with age steadilythrough the fifth decade of life.

Historically, studies have generally attributed loss of accommodation tothe hardening of the crystalline lens with age and more specifically, toan increase in the Young's Modulus of Elasticity of the lens material.More recent studies have examined the effect of aging on the relativechange in material properties between the nucleus and cortex. Thesestudies have provided varying theories and data with respect to thehardening of the lens. In general, such studies have essentiallyproposed the theory that the loss of flexibility is the result of anincrease in the Young's Modulus of Elasticity of the nucleus and/orcortex material. Such studies have viewed this hardening as the primaryfactor in the loss of accommodative amplitude with age and hence thecause of presbyopia.

Although the invention is not bound by it, the present specificationpostulates a different theory of how this loss of lens flexibilityoccurs to cause presbyopia. In general, it is postulated the structureof the lens rather than the material properties of the lens plays agreater role in loss of flexibility and resultant presbyopia than waspreviously understood. Thus, contrary to the teachings of the priorstudies in this field as set forth above, material elasticity is not thedominate cause of presbyopia. Rather, it is postulated that it is thestructure of the lens and changes in that structure with age that is thedominant cause of presbyopia. Thus, without being limited to or bound bythis theory, the present invention discloses a variety of methods andsystems to provide laser treatments to increase the flexibility of thelens, based at least in part on the structure of the lens and structuralchanges that occur to the lens with aging. The present invention furtherdiscloses providing laser treatments to increase the flexibility of thelens that are based primarily on the structure of the lens andstructural changes that occur to the lens with aging.

Accordingly, the postulated theory of this specification can beillustrated for exemplary purposes by looking to and examining a simplehypothetical model. It further being understood this hypothetical modelis merely to illustrate the present theory and not to predict how a lenswill react to laser pulses, and/or structural changes. To understand howimportant structure alone can be, consider a very thin plank of wood,say 4 ft by 4 ft square but 0.1 inch thick. This thin plank is not verystrong and if held firmly on one end, it does not take much force tobend this thin plank considerably. Now consider five of these same 0.1inch thickness planks stacked on top of each other, but otherwise notbound or tied together. The strength would increase and for the sameforce a somewhat smaller deflection will occur. Now, consider takingthose same five planks and fastening them together with many screws orby using very strong glue, or by using many C-Clamps to bind themtogether. The strength of the bound planks is much higher and thedeflection seen from the same force would be much smaller.

Without saying this simple model reflects the complex behavior of thelens, we generally hypothesize that when considering a volume of lensmaterial, especially near the poles (AP axis), that is essentially boundby increased friction and compaction due to aging, that separating thosebound layers into essentially unbound layers will increase thedeflection of those layers for the same applied force and hence increaseflexibility of the lens. Applicants, however, do not intend to be boundby the present theory, and it is provided solely to advance the art, andis not intended to and does not restrict or diminish the scope of theinvention,

Thus, further using this model for illustration purposes, under theprior theories and treatments for presbyopia, the direction wasprincipally toward the material properties, i.e., Modulus of thematerial in the stack, rather than on the structure of the stack, i.e.,whether the layers were bound together. On the other hand, the presentlypostulated theory is directed toward structural features and the effectsthat altering those features have on flexibility.

In general, current presbyopia treatments tend to be directed towardalternatives to increasing the amplitude of accommodation of the naturalcrystalline lens. These treatments include a new class of artificialaccommodative Intraocular Lenses (IOL's), such as the EyeonicsCRYSTALENS, which are designed to change position within the eye;however, they offer only about 1 diopter of objectively measuredaccommodative amplitude, while many practitioners presently believe 3 ormore diopters are required to restore normal visual function for nearand far objects. Moreover, researchers are pursuing techniques andmaterials to refill the lens capsule with synthetic materials.Additionally, present surgical techniques to implant artificialaccommodative IOL's are those developed for the more serious conditionof cataracts. It is believed that practitioners are reluctant at thepresent time to replace a patient's clear albeit presbyopic naturalcrystalline lens, with an accommodative IOL due to the risks of thisinvasive surgical technique on a patient who may simply wear readingglasses to correct the near vision deficiency. However, developments mayoffer greater levels of accommodative amplitude in implantable devicesand refilling materials. To better utilize such device improvements andto increase the accommodative amplitude of existing implantable devices,improved surgical techniques are provided herein as a part of thepresent invention.

Refractive error, typically due to the length of the eye being too long(myopia) or to short (hyperopia) is another very common problemeffecting about one-half of the population. Laser surgery on the cornea,as proposed by Trokel and L'Esperance and improved by Frey and others,does offer effective treatment of refractive errors but factors such ashigher degrees of refractive error, especially in hyperopia, thincorneas or a changing refractive error with time, such as that broughton by presbyopia, limit the clinical use of laser corneal surgery formany.

Cataracts, or the condition when the natural crystalline lens becomesopaque and clouds vision, occurs in millions of people per year and aretreated effectively with a surgical techniques such as ultrasonicphacoemulsification pioneered by Kelman 30 years ago. Although thetechniques have been refined over the years, safety concerns from oculartrauma, especially to the corneal endothelium from the ultrasonic energyrequired to break up a hardened cataract is undesirable; especially forthose with a compromised corneal endothelium, such as those with FuchsDystrophy. Moreover, the use of lasers in the treatment of cataracts hasa further issue. Cataracts scatter light, including laser light and thuscan prevent a laser treatment beam from having the desired tissueeffect. Accordingly, as provided in detail in this specification hereinimprovements in the delivery of lasers to cataractous tissue areprovided.

SUMMARY

Provided herein are embodiments of the present invention. Accordingly,there is provided method and system for delivering a laser beam to alens of an eye that utilize the steps of providing a laser, an opticalpath for directing a laser beam from the laser to the lens of the eye,determining the shape and position of the lens with respect to a fixedpoint, and focusing a laser beam to a location in the lens of the eye,wherein that location was determined based at least in part upon dataand/or information from the determining step.

There is further provided a method and system for delivering a laserbeam in the lens of the eye in a predetermined shot pattern that utilizeas series of shots that form a shell cut, a partial shell cut, a lasersuture cut and/or a volumetric shaped removal, which essentiallyfollowing the shape of a suture layer of the lens, i.e., a layer shapeof the lens.

There is further provided a method and system for directing a laser beamin the lens of the eye in a predetermined shot pattern such that a gridcut pattern is formed. The delivery of this grid cut pattern resultingin the formation of cubes, which can then be removed from the lenscapsule and a replacement material placed therein.

There is further provided a method and system for delivering a laserbeam to a lens of an eye that utilize the steps of providing a laser,determining the shape and position of the lens with respect to a fixedpoint, directing the laser beam in the lens of the eye in a pattern ofshots, which is based in part upon the geometry of a natural human lensand focusing the laser shots in the lens of the eye based in part uponinformation obtained from the determining step.

There is further provided a system and method for directing a laser beamin a shot pattern to from an annular ring shaped capsulorhexis.

There is further provided a method and system for creating a shell cut,a partial shell cut, a laser suture cut, and/or a volumetric shapedremoval within a lens of an eye that utilize the steps of providing alaser, directing the laser beam to the lens of the eye, said lens havingan outer surface and said outer surface having a shape, directing thelaser beam in the lens of the eye in a predetermined shot pattern, saidshot pattern comprising as series of shots that form a shell cut, apartial shell cut, a laser suture cut, and/or a volumetric shapedremoval within a lens of an eye and which essentially following theshape of the outer surface of the lens. It is further provided thatthese shell cuts, partial shell cuts, laser suture cuts, and/orvolumetric shaped removals may generally corresponds to a suture layerof the lens selected from the group consisting of suture layers having3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, and fractions between 3 and15 sutures.

There is further provided a system and method for creating a shell cutand/or partial shell cut within a lens of an eye that utilize the stepsof directing a laser beam to the lens of the eye in a predetermined shotpattern that utilize as series of shots that form a shell cut and/orpartial shell cut, which has a flower like shape having a contour thatgenerally follows approximately the last 15% of the fiber length fromthe end of the fiber.

There is further provided a system and method for modifying the gradientindex of a lens of an eye that utilize the steps of providing a laser,directing the laser beam to the lens of the eye in a predetermined shotpattern, said shot pattern comprising as series of shots that form atleast two shapes of different densities, which shapes are nested withineach other, positioned entirely within the lens and follow the outersurface of the lens.

There is further provided a system for treating conditions of the lenscomprising a laser, laser focusing optics, a scanner and a controlsystem that has a plurality of means for directing in cooperation withthe laser, the scanner and the laser focusing optics, laser shot patternthat provide the ability to performing a lens material extraction, thetreatment of presbyopia, and the treatment of refractive error.

There is further provided a system for delivering a laser to an eye andfor obtaining stereo images of the eye comprising a laser, focusingoptics, a scanner and a camera. Wherein the scanner is opticallyassociated with the laser and the camera so that the scanner has thecapability to provide stereo pairs of images of the eye and deliver alaser beam from the laser to the eye.

There is further provided a system for delivering a laser to an eye andfor determining the position of the eye comprising a patient support, alaser, optics for delivering a laser beam, a control system fordelivering the laser beam to the lens of the eye in a particularpattern, a lens position determination apparatus, and, a laser patientinterface.

One of ordinary skill in the art will recognize, based on the teachingsset forth in these specifications and drawings, that there are variousembodiments and implementations of these teachings to practice thepresent invention. Accordingly, the embodiments in this summary are notmeant to limit these teachings in any way.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 1A are cross sectional representations of the human eye.

FIG. 2 is a block schematic diagram of a type of system for delivering alaser beam shot pattern to the lens of an eye according to the teachingsof the present invention.

FIG. 2A is a block schematic diagram of illustrative components forminga portion of a system for delivering a laser beam shot pattern to thelens of an eye according to the teachings of the present invention.

FIG. 3 is a diagram of the anterior surface of a lens along the AP axisillustrating a laser shot pattern having a flower like shape which has acontour generally following approximately the last 15% of the fiberlength from the end of the fiber.

FIGS. 4A, 4B, 4C, 4D and 4E are diagrams representing elevation views ofthe geometry used for the development of laser shot patterns based uponthe structure of the fetal nucleus (three suture branch nucleus) as itis rotated from the posterior view 4A through and to the anterior view4E.

FIGS. 5A, 5B, and 5C are diagrams representing posterior, side andanterior elevation views, respectively, of the geometry used for thedevelopment of laser shot patterns based upon the structure of theinfantile nucleus (six suture branch nucleus).

FIGS. 6A, 6B and 6C are diagrams representing posterior, side andanterior elevation views, respectively of the geometry used for thedevelopment of laser shot patterns based upon the structure of theadolescent nucleus (nine suture branch nucleus).

FIGS. 7A, 7B and 7C are diagrams representing posterior, side andanterior elevation views, respectively of the geometry used for thedevelopment of laser shot patterns based upon the structure of the anadult nucleus (12 suture branch).

FIGS. 8 aid 8A are perspective cutout views of an adult lensrepresenting the placement of essentially concentric shells inaccordance with the teachings of the present invention.

FIG. 9 is a cross-section drawing of the lens relating to Burd modeling.

FIG. 10 is a cross-section drawing of a lens based upon Burd modeling.

FIG. 11 is a cross-section drawing of a lens based upon Burd modeling.

FIG. 12 is a cross-section drawing of a lens based upon Burd modeling.

FIG. 13 is a cross-section drawing of a lens showing the placement of ashell laser shot pattern in accordance with the teachings of the presentinvention.

FIG. 14 is a cross-section drawing of a lens showing the placement of ashell laser shot pattern in accordance with the teachings of the presentinvention.

FIG. 15 is a cross-section drawing of a lens showing the placement of apartial shell laser shot pattern in accordance with the teachings of thepresent invention.

FIG. 16 is a cross-section drawing of a lens showing the placement of apartial shell laser shot pattern in accordance with the teachings of thepresent invention.

FIG. 17 is a cross-section drawing of a lens showing the placement of ashell laser shot pattern in accordance with the teachings of the presentinvention.

FIGS. 18-24 are cross-section drawings of a lens showing the placementof a volumetric removal laser shot patterns in accordance with theteachings of the present invention.

FIG. 25 is a cross-section drawing of a lens showing the placement of acube laser shot pattern in accordance with the teachings of the presentinvention.

FIGS. 26-27 are cross-section drawings of a lens showing the placementof a gradient index modification laser shot patterns in accordance withthe teachings of the present invention.

FIGS. 28A, C and E diagrams depicting laser suture cut shot patterns onthe anterior portion of a lens of the present invention.

FIGS. 28B, D, and F are diagrams illustrating the placement of the shotpatterns of FIGS. 28A, C, and E respectively.

FIG. 29 is a diagram illustrating the relative placement of the shotpatterns of FIGS. 28A, C, and E, if performed in the same lens.

FIGS. 30A-D are diagrams of the cross-section of a lens illustrating acapsulorhexis shot pattern of the present invention.

FIGS. 31A to 31D are illustrations of gradient index modifications ofthe lens in accordance with the present inventions.

DETAILED DESCRIPTION OF THE DRAWINGS AND THE PREFERRED EMBODIMENTS

In general, the present invention provides a system and method forincreasing the amplitude of accommodation and/or changing the refractivepower and/or enabling the removal of the clear or cataractous lensmaterial of a natural crystalline lens. Thus, as generally shown in FIG.2 there is provided a system for delivering a laser beam shot pattern tothe lens of an eye comprising: a patient support 201; a laser 202;optics for delivering the laser beam 203; a control system fordelivering the laser beam to the lens in a particular pattern 204, whichcontrol system 204 is associated with and/or interfaces with the othercomponents of the system as represented by lines 205; a means fordetermining the position of lens with respect to the laser 206, whichmeans 206 receives an image along path 211 of the lens of the eye; and alaser patient interface 207.

The patient support 201 positions the patent's body 208 and head 209 tointerface with the optics for delivering the laser beam 203.

In general, the laser 202 should provide a beam 210 that is of awavelength that transmits through the cornea, aqueous and lens. The beamshould be of a short pulse width, together with the energy and beamsize, to produce photodisruption. Thus, as used herein, the term lasershot or shot refers to a laser beam pulse delivered to a location thatresults in photodisruption. As used herein, the term photodisruptionessentially refers to the conversion of matter to a gas by the laser. Inparticular, wavelengths of about 300 nm to 2500 nm may be employed.Pulse widths from about 1 femtosecond to 100 picoseconds may beemployed. Energies from about a 1 nanojoule to 1 millijoule may beemployed. The pulse rate (also referred to as pulse repetition frequency(PRF) and pulses per second measured in Hertz) may be from about 1 KHzto several GHz. Generally, lower pulse rates correspond to higher pulseenergy in commercial laser devices. A wide variety of laser types may beused to cause photodisruption of ocular tissues, dependent upon pulsewidth and energy density. Thus, examples of such lasers would include:the Delmar Photonics Inc. Trestles-20, which is a Titanium Sapphire(Ti:Sapphire) oscillator having a wavelength range of 780 to 840 nm,less than a 20 femtosecond pulse width, about 100 MHz PRF, with 2.5nanojoules; the Clark CPA-2161, which is an amplified Ti:Sapphire havinga wavelength of 775 nm, less than a 150 femtosecond pulse width, about 3KHz PRF, with 850 microjoules; the IMRA FCPA (fiber chirped pulseamplification) μjewel D series D-400-HR, which is a Yb:fiberoscillator/amplifier having a wavelength of 1045 nm, less than a 1picosecond pulse width, about 5 MHz PRF, with 100 nanojoules; the LumeraStaccato, which is a Nd:YVO4 having a wavelength of 1064 nm, about 10picosecond pulse width, about 100 KHz PRF, with 100 microjoules; and,the IMRA FCPA (fiber chirped pulse amplification) μjewel D seriesD-400-NC, which is a Yb:fiber oscillator/amplifier having a wavelengthof 1045 nm, less than a 100 picosecond pulse width, about 200 KHz PRF,with 4 microjoules.

In general, the optics for delivering the laser beam 203 to the naturallens of the eye should be capable of providing a series of shots to thenatural lens in a precise and predetermined pattern in the x, y and zdimension. The optics should also provide a predetermined beam spot sizeto cause photodisruption with the laser energy reaching the naturallens. Thus, the optics may include, without limitation: an x y scanner;a z focusing device; and, focusing optics. The focusing optics may beconventional focusing optics, and/or flat field optics and/ortelecentric optics, each having corresponding computer controlledfocusing, such that calibration in x, y, z dimensions is achieved. Forexample, an x y scanner may be a pair of closed loop galvanometers withposition detector feedback. Examples of such x y scanners would be theCambridge Technology Inc. Model 6450, the SCANLAB hurrySCAN and theAGRES Rhino Scanner. Examples of such z focusing devices would be thePhsyik International Peizo focus unit Model ESee Z focus control and theSCANLAB varrioSCAN.

In general, the control system for delivering the laser beam 204 may beany computer, controller, and/or software hardware combination that iscapable of selecting and controlling x y z scanning parameters and laserfiring. These components may typically be associated at least in partwith circuit boards that interface to the x y scanner, the z focusingdevice and/or the laser. The control system may also, but does notnecessarily, have the further capabilities of controlling the othercomponents of the system as well as maintaining data, obtaining data andperforming calculations. Thus, the control system may contain theprograms that direct the laser through one or more laser shot patterns.

In general, the means for determining the position of the lens withrespect to the laser 206 should be capable of determining the relativedistance with respect to the laser and portions of the lens, whichdistance is maintained constant by the patient interface 207. Thus, thiscomponent will provide the ability to determine the position of the lenswith respect to the scanning coordinates in all three dimensions. Thismay be accomplished by several methods and apparatus. For example, x ycentration of the lens may i)e accomplished by observing the lensthrough a coboresighed camera system and display or by using direct viewoptics and then manually positioning the patients'eye to a known center.The z position may then be determined by a range measurement deviceutilizing optical triangulation or laser and ccd system, such as theMicro-Epsilon opto NCDT 1401 laser sensor and/or the Aculux Laser RangerLR2-22. The use of a 3-dimensional viewing and measurement apparatus mayalso be used to determine the x, y and z positions of the lens. Forexample, the Hawk 3 axis non-contact measurement system from VisionEngineering could be used to make these determinations. Yet a furtherexample of an apparatus that can be used to determine the position ofthe lens is a 3-dimension measurement apparatus. This apparatus wouldcomprise a camera, which can view a reference and the natural lens, andwould also include a light source to illuminate the natural lens. Suchlight source could be a structured light source, such as for example aslit illumination designed to generate 3-dimensional information basedupon geometry.

A further component of the system is the laser patient interface 207.This interface should provide that the x, y, z position between thenatural lens and the laser remains fixed during the procedure, whichincludes both the measurement steps of determining the x y z positionand the delivery step of delivering the laser to the lens in a shotpattern. The interface device may contain an optically transparentapplanator. One example of this interface is a suction ring applanatorthat is fixed against the outer surface of the eye and is thenpositioned against the laser optical housing, thus fixing the distancebetween the laser, the eye and the natural lens. The reference marks forthe 3-dimensional viewing and measuring apparatus may also be placed onthis applanator. A further example of a laser patient interface is adevice having a lower ring, which has suction capability for affixingthe interface to the eye. The interface further has a flat bottom, whichpresses against the eye flattening the eye's shape. This flat bottom isconstructed of material that transmits the laser beam and alsopreferably, although not necessarily, transmits optical images of theeye within the visible light spectrum. The upper ring has a structurefor engaging with the housing for the laser optics and/or some structurethat is of known distance from the laser along the path of the laserbeam and fixed with respect to the laser. The flat bottom further has areference, which consists of three reference marks. Although three marksare provided in this example to make up the reference, the reference mayconsist of only a single mark or several marks. Further examples of suchdevices are generally disclosed in US D462442, US D462443, and USD459807S, the disclosures of which are hereby incorporated by reference.As an alternative to an applanator, the interface may be a cornealshaped transparent element whereby the cornea is put into direct contactwith the interface or contains an interface fluid between.

An illustrative combination utilizing by way of example specific opticsfor delivering the laser beam 203 and means for determining the positionof the lens 206, is shown in part, in FIG. 2A. FIG. 2A is a moredetailed schematic diagram of a configuration of the system of FIG. 2.Thus, the example of FIG. 2A provides a laser 202, laser optics fordelivering the laser beam 203, which optics comprise a beam expandertelescope 220, a z focus mechanism 221, a beam combiner 222, an x yscanner 223, and focusing optics 224. There is further provided in FIG.2A relay optics 230, camera optics with zoom and focus 231, and a ccdcamera 232, which components form a part of a three-dimensional viewingand measuring apparatus. Moreover, these components 230, 231 and 232 incombination with a light source 233, the reference mark 212 and thescanner 223 function as a means for determining the position of the lens206.

This combination of FIG. 2A utilizes the x y scanner 223 to createstereoscopic images of the lens with only a single ccd camera 232.Optical images of the eye 213 and in particular optical images of thenatural lens 103 of the eye 213 are conveyed along a path 211. This path211 follows the same path as the laser beam 210 from the natural lens103 through the laser patient interface 207, the focusing optics 224,the x y scanner 223 and the beam combiner 222. This combination of FIG.2A further comprises: a laser patient interface 207, with a referencemark 212; and a light source 233, which could be for example uniformillumination, a slit illumination, or other structured light sourcedesigned to enhance 3-dimensional accuracy. The light source, in part,provides illumination of the natural lens of the patient's eye for thepurposes of determining the 3-dimensional position of the lens. Thus,either stereoscopic images and/or the information from the camera aresent to a controller and/or computer (not shown in FIG. 2A) for furtherprocessing and use in determining 3-dimensional positions of the lens.Stereo images may be generated by commanding the scanner to go to andpause at a nominal left position and then electronically trigger thecamera and controller to capture and store the left image; then commandthe scanner/camera/controller similarly to capture and store rightimage. This sequence may be repeated in a periodic manner. These leftand right images can be processed by the controller to generate theposition and shape of the lens. The left and right images can bedisplayed using a stereo video monitor. Camera images or stereo imagesmay also be used to measure suture geometry and orientation in thepatients lens, which can be used to determine the parameters of suturebased shot patterns and to align suture based shot patterns to thepatients lens suture geometry and orientation. The combinationillustrated in FIG. 2A provides 3-dimensional information that can beused to determine the shape of the lens, including the anterior andposterior surfaces thereof. This information can also be used tovisualize the structure of the lens, including sutures. Moreover, theinformation about the lens obtained from the combination of FIG. 2A canfurther be used in determining the laser shot pattern and laser shotplacement with respect to lens shape and/or structure.

FIG. 2 and FIG. 2A are block schematic diagrams and thus the relativepositions and spacing of the components illustrated therein are by wayof example. Accordingly, the relative placements of these componentswith respect to one another may be varied and all or some of theirfunctions and components may be combined.

FIGS. 4A-E illustrate the three branched or Y suture geometry in thecontext of the structures found in the fetal nucleus 415 of the lens.Thus, these figures provide a more detailed view of the structuresillustrated as layer 130, which encompasses layer 122 of FIG. 1A. InFIGS. 4A-E the view of the inner layer of the lens is rotated stepwisefrom the posterior side FIG. 4A to the anterior side FIG. 4E of thelens. Thus, this layer of the lens has three posterior suture lines 401,402, and 403. This layer also has three anterior suture lines 412, 413and 414. The anterior suture lines are longer than the posterior suturelines and these lines are staggered when viewed along the anterior toposterior (AP) axis 411. The lens fibers, which form the layers of thenucleus, are shown by lines 404, it being understood that these are onlyillustrative lines and that in the actual natural layer of the lensthere would be many times more fibers present. To aid in illustratingthe structure and geometry of this layer of the nucleus representativefibers 405, 406, 407, 408, 409 and 410 have been exaggerated andindividually shaded in FIGS. 4A-E. Thus, as the view of the lens nucleusis rotated from posterior to anterior the positions of theserepresentative fibers, there relationship to each other, and thererelationship to the suture lines is illustrated.

The length of the suture lines for the anterior side are approximately75% of the equatorial radius of the layer or shell in which they arefound. The length of the suture lines for the posterior side areapproximately 85% of the length of the corresponding anterior sutures,i.e, 64% of the equatorial radius of that shell.

The term—essentially follows—as used herein would describe therelationship of the shapes of the outer surface of the lens and thefetal nucleus 415. The fetal nucleus is a bicorvex shape. The anteriorand posterior sides of the lens have different curvatures, with theanterior being flatter. These curvatures generally follow the curvatureof the cortex and the outer layer and general shape of the lens. Thus,the lens can be viewed as a stratified structure consisting of longcrescent fiber cells arranged end to end to form essentially concentricor nested shells.

As provided in greater detail in the following paragraphs and by way ofthe following examples, the present invention utilizes this and thefurther addressed geometry, structure and positioning of the lenslayers, fibers and suture lines to provide laser shot patterns forincreasing the accommodative amplitude of the lens. Although not beingbound by this theory, it is presently believed that it is the structure,positioning and geometry of the lens and lens fibers, in contrast to thematerial properties of the lens and lens fibers, that gives rise to lossof accommodative amplitude. Thus, these patterns are designed to alterand affect that structure, positioning and/or geometry to increaseaccommodative amplitude.

FIGS. 5A-C illustrate the six branched or star suture geometry in thecontext of the structure found in the infantile layer of the nucleus 515of the lens. Thus, these figures provide a more detailed view of thestructures illustrated as layer 124 of FIG. 1A. In FIGS. 5A-C the viewof the layer of the lens is rotated from the posterior side FIG. 5A to aside view FIG. 5B to the anterior side FIG. 5C. Thus, this layer of thenucleus has six posterior suture lines 501, 502, 503, 504, 505, and 506.This layer of the nucleus also has six anterior suture lines 509, 510,511, 512, 513, and 514. The anterior suture lines are longer than theposterior suture lines and these lines are staggered when viewed alongthe AP axis 508. The lens fibers, which form the layers of the nucleus,are shown by lines 507, it being understood that these are onlyillustrative lines and that in the actual natural layer of the lensthere would be many times more fibers present.

The shape of the outer surface of the lens essentially follows theinfantile nucleus 515, which is a biconvex shape. Thus, the anterior andposterior sides of this layer of the lens have different curvatures,with the anterior being flatter. These curvatures generally follow thecurvature of the cortex and the outer layer and general shape of thelens. These curvatures also generally follow the curvature of the fetalnucleus 415. Thus, the lens can be viewed as a stratified structureconsisting of long crescent fiber cells arranged end to end to formessentially concentric or nested shells, with the infantile nucleus 515having the fetal nucleus 415 nested within it. As development continuesthrough adolescence, additional fiber layers grow containing between 6and 9 sutures.

FIGS. 6A-C illustrate the nine branched or star suture geometry in thecontext of the structure found in the adolescent layer of the nucleus611 of the lens. Thus, these figures provide a more detailed view of thestructures illustrated as layer 126 of FIG. 1A. In FIGS. 6A-C the viewof the layer of the lens is rotated from the posterior side FIG. 6A to aside view FIG. 6B to the anterior side FIG. 6C. Thus, this layer of thenucleus has nine posterior suture lines 601, 602, 603, 604, 605, 606,607, 608 and 609. This layer of the nucleus also has nine anteriorsuture lines 612, 613, 614, 615, 616, 617, 618, 619 and 620. Theanterior suture lines are longer than the posterior suture lines andthese lines are staggered when viewed along the AP axis 610. The lensfibers, which form the layers of the nucleus, are shown by lines 621; itbeing understood that these are only illustrative lines, and that in theactual natural layer of the lens there would be many times more fiberspresent.

The outer surface of the cornea follows the adolescent nucleus 611,which is a biconvex shape. Thus, the anterior and posterior sides ofthis layer have different curvatures, with the anterior being flatter.These curvatures generally follow the curvature of the cortex and theouter layer and general shape of the lens. These curvatures alsogenerally follow the curvature of the fetal nucleus 415 and theinfantile nucleus 515, which are nested within the adolescent nucleus611. Thus, the lens can be viewed as a stratified structure consistingof long crescent fiber cells arranged end to end to form essentiallyconcentric or nested shells. As development continues through adulthood,additional fiber layers grow containing between 9 and 12 sutures.

FIGS. 7A-C illustrates the twelve branched or star suture geometry inthe context of the structure found in the adult layer of the nucleus 713of the lens. Thus, these figures provide a more detailed view of theadult layer 128 depicted in FIG. 1A. In FIGS. 7A-C the view of the layerof the lens is rotated from the posterior side FIG. 7A to a side viewFIG. 7B to the anterior side FIG. 7C. Thus, the adult layer of thenucleus has twelve posterior suture lines 701, 702, 703, 704, 705, 706,707, 708, 709, 710, 711, and 712. This layer of the nucleus also hastwelve anterior suture lines 714-725. The anterior suture lines arelonger than the posterior suture lines and these lines are staggeredwhen viewed along the AP axis 726. The lens fibers, which form thelayers of the nucleus, are shown by lines 728; it being understood thatthese are only illustrative lines, and that in the actual natural layerof the lens there would be many times more fibers present.

The adult nucleus 713 is a biconvex shape that follows the outer surfaceof the lens. Thus, the anterior and posterior sides of this layer havedifferent curvatures, with the anterior being flatter. These curvaturesfollow the curvature of the cortex and the outer layer and shape of thelens. These curvatures also generally follow the curvature of theadolescent nucleus 611, the infantile nucleus 515 and the fetal nucleus415 and the embryonic nucleus, which are essentially concentric to andnested within the adult nucleus 611. Thus, the lens can be viewed as astratified structure consisting of long crescent fiber cells arrangedend to end to form essentially concentric or nested shells.

A subsequent adult layer having 15 sutures may also be present in someindividuals after age 40. This subsequent adult layer would be similarto the later adult layer 713 in general structure, with the recognitionthat the subsequent adult layer would have a geometry having moresutures and would encompass the later adult layer 713; and as such, thesubsequent adult layer would be the outermost layer of the nucleus andwould thus be the layer further from the center of the nucleus and thelayer that is youngest in age.

In general, the present invention provides for the delivery of the laserbeam in patterns that utilize, or are based at least in part on, thelens suture geometry and/or the curvature of the lens and/or the variouslayers within the nucleus; and/or the curvatures of the various layerswithin the nucleus; and/or the suture geometry of the various layerswithin the nucleus. As part of the present invention the concept ofmatching the curvature of the anterior ablations to the specificcurvature of the anterior capsule, while having a different curvaturefor posterior ablations, which in turn match the posterior curvature ofthe lens is provided. Anterior and posterior curvatures can be based onKuszak aged lens models, Burd's numeric modeling, Burd et al. VisionResearch 42 (2002) 2235-2251, or on specific lens measurements, such asthose that can be obtained from the means for determining the positionof the lens with respect to the laser. Thus, in general, these laserdelivery patterns are based in whole and/or in part on the mathematicalmodeling and actual observation data regarding the shape of the lens,the shape of the layers of the lens, the suture pattern, and theposition of the sutures and/or the geometry of the sutures.

Moreover, as set forth in greater detail, it is not necessary that thenatural suture lines of the lens or the natural placement of the layersof the lens be exactly replicated in the lens by the laser shot pattern.In fact, exact replication of these natural structures by a laser shotpattern, while within the scope of the invention, is not required, andpreferably is not necessary to achieve an increase in accommodativeamplitude. Instead, the present invention, in part, seeks to generallyemulate the natural lens geometry, structures and positioning and/orportions thereof, as well as build upon, modify and reposition suchnaturally occurring parameters through the use of the laser shotpatterns described herein.

Accordingly, laser beam delivery patterns that cut a series ofessentially concentric, i.e., nested, shells in the lens may beemployed. Preferably, the shells would essentially follow the anteriorand posterior curvature of the lens. Thus, creating in the lens a seriesof cuts which resemble the nucleus layers of FIGS. 4, 5, 6 and 7. Thesecuts may follow the same geometry, i.e., shape and distance from thecenter, of these layers or may follow only a part of that geometry. Oneexample of these shells is illustrated in FIG. 8, which provides a lens103, a first shell cut 801, a first shell 802, a second shell cut 803, asecond shell 804 and a third shell cut 805. The adult nucleus 128 andcortex 113 are also provided. Thus, the term shell refers to the lensmaterial and the term shell cut refers to the laser beam deliverypattern and consequently the placement of the laser beam shots in thelens in accordance with that pattern. More or less shell cuts, and thusshells may be utilized. Moreover, the cuts may be such that they ineffect create a complete shell, i.e., the shell and shell cutscompletely encompass a volume of lens material. The cuts may also besuch that less than a complete shell is formed. Thus, the creation ofpartial shells, by the use of partial shell cuts, may be employed. Suchpartial cuts would for example be only a portion of a shell e.g., theanterior quartile, the anterior half, the posterior quartile, stackedannular rings, staggered annular rings, and/or combinations thereof.Such partial shells and shell cuts may be any portion of a threedimensional form, including ellipsoid, spheroids and combinationsthereof as those terms are used in their broadest sense that in generalfollows the contours of the lens, capsule, cortex, nucleus, and/or thelayers of the lens including the layers of the nucleus. Moreover, theuse of complete and partial shells and shell cuts may be used in asingle lens. Thus, by way of illustration of this latter point, thefirst and second cuts 801 and 803 are annular cuts, while the third cutis a complete cut.

A further use of partial shells is to have the shape of the shellsfollow the geometry and/or placement of the suture lines. Thus, partialpie shaped shells are created, by use of partial pie shaped shell cuts.These cuts may be placed in between the suture lines at the variouslayers of the lens. These partial shells may follow the contour of thelens, i.e., have a curved shape, or they may be flatter and have a moreplanar shape or be flat. A further use of these pie shape shells andshell cuts would be to create these cuts in a suture like manner, butnot following the natural suture placement in the lens. Thus, a suturelike pattern of cuts is made in the lens, following the general geometryof the natural lens suture lines, but not their exact position in thelens. In addition to pie shaped cuts other shaped cuts may be employed,such as by way of illustration a series of ellipses, rectangular planesor squares.

A further use of partial shells and/or planar partial shells is tocreate a series of overlapping staggered partial shells by usingoverlapping staggered partial shell cuts. In this way essentiallycomplete and uninterrupted layers of lens material are disruptedcreating planar like sections of the lens that can slide one atop theother to thus increase accommodative amplitude. These partial shells canbe located directly atop each other, when viewed along the AP axis, orthey could be slightly staggered, completely staggered, or anycombination thereof.

In addition to the use of shells and partial shells, lines can also becut into the lens. These lines can follow the geometry and/or geometryand position of the various natural suture lines. Thus, a laser shotpattern is provided that places shots in the geometry of one or more ofthe natural suture lines of one or more of the various natural layers ofthe lens as shown in FIGS. 4, 5, 6, and 7, as well as in the 15 sutureline layer, or it may follow any of the other patterns in the continuumof layers in the lens. These shot patterns can follow the generalgeometry of the natural suture lines, i.e., a series of star shapes withthe number of legs in each star increasing as their placement moves awayfrom the center of the lens. These star shaped shot patterns may followthe precise geometry of the natural suture patterns of the layers of thelens; or it can follow the exact geometry and placement of the sutures,at the same distances as found in the natural lens or as determined bymodeling of the natural lens. In all of these utilizations of starpatterns one or more stars may be cut. The length of the lines of thelegs of the star may be the longer, shorter or the same length as thenatural suture lines. Moreover, if the length is shorter than thenatural length of the suture lines, it may be placed toward the centerof the star shape, i.e. the point where the lines join each other, ortowards the end of the suture line, i.e., the point furthest on thesuture line from the joining point. Further, if the cut is towards theend of the suture line it may extend beyond the suture line or may beco-terminus therewith. Moreover, partial star shaped cuts can be used,such as cuts having a “V” shape, or vertical or horizontal or at anangle in between. These linear cuts, discussed above, are in generalreferred to herein as laser created suture lines. Moreover, lasercreated suture lines may be grouped together to in effect form a shellor partial shell.

At present, it is theorized that the use of cuts near the end of thesuture lines will have the greatest effect on increasing accommodativeamplitude because it is believed that the ends of fibers near theanterior and posterior poles (the point where the AP axis intersects thelens) of the lens are more free to move then the portions of fibers nearthe equator where there is a greater number of gap junctions which bindfiber faces. At present, it is postulated that it is approximately thelast 15% of the fiber length that is most free in the youthful lens withhigh accommodative amplitude. It is further theorized that fiber layerstend to become bound with age due to a combination of increase insurface roughness and compaction due to growth of fiber layers above.Thus, as illustrated in FIG. 3 a shot pattern 301 is provided to ananterior portion of a layer 302 of the lens. This shot pattern 301 has acontour 303 that follows the contour of approximately the last 15% offiber length of fibers, represented by lines 304. Thus, the shell cutresembles the shape of a flower. Additionally, the number of petals inthe flower shaped shell should correspond to the number of suture lines305 at that growth layer. Thus, it is theorized that this partial shellcut and/or cuts will have the effect of unbinding the layers andreturning the lens to a more youthful increased amplitude ofaccommodation. Similarly, using partial shells, annular partial shellsor planar partial shells in this general area, i.e., the general area ator near the ends of the suture lines, may be employed for the samereasons. This theory is put forward for the purposes of providingfurther teaching and to advancing the art. This theory, however, is notneeded to practice the invention; and the invention and the claimsherein are not bound by or restricted by or to this theory.

The use of laser created suture lines, including star shaped patternsmay also be used in conjunction with shells, partial shells and planarpartial shells. With a particular laser shot pattern, or series of shotpatterns, employing elements of each of these shapes. These patterns maybe based upon the geometry shown in FIGS. 4-7 as well as the 15 sutureline geometry discussed herein; they may follow that geometry exactly,in whole or in part; and/or they may follow that geometry, in whole orin part, as well as following the position of that geometry in the lens.Although a maximum of 15 suture lines is known in the natural lens, morethan 15 laser created suture lines may be employed. Moreover, asprovided herein, the lens has multiple layers with a continuum of suturelines ranging from 3 to 15 and thus, this invention is not limited tothe suture patents of FIGS. 4-7, but instead covers any number of suturelines from 3 to 15, including fractions thereof.

The delivery of shot patterns for the removal of lens material isfurther provided. A shot pattern that cuts the lens into small cubes,which cubes can then be removed from the lens capsule is provided. Thecubes can range in size from a side having a length of about 100 μm toabout 4 mm, with about 500 μm to 2 mm being a preferred size.Additionally, this invention is not limited to the formation of cubesand other volumetric shapes of similar general size may be employed. Ina further embodiment the laser is also used to create a small opening,capsulorhexis, in the lens anterior surface of the lens capsule forremoval of the sectioned cubes. Thus, this procedure may be used totreat cataracts. This procedure may also be used to remove a lens havingopacification that has not progressed to the point of being cataractous.This procedure may further be used to remove a natural lens that isclear, but which has lost its ability to accommodate. In all of theabove scenarios, it being understood that upon removal of the lensmaterial the lens capsule would subsequently house a suitablereplacement, such as an IOL, accommodative IOL, or synthetic lensrefilling materials. Moreover, the size and the shape of thecapsulorhexis is variable and precisely controlled and preferably is in2 mm or less diameter for lens refilling applications and about 5 mm forIOLs. A further implementation of the procedure to provide acapsulorhexis is to provide only a partially annular cut and thus leavea portion of the capsule attached to the lens creating a hinged flaplike structure. Thus, this procedure may be used to treat cataracts.

It is further provided that volumetric removal of the lens can beperformed to correct refractive errors in the eye, such as myopia,hyperopia and astigmatism. Thus, the laser shot pattern is such that aselected volume and/or shape of lens material is removed byphotodisruption from the lens. This removal has the affect ofalternating the lens shape and thus reducing and/or correcting therefractive error. Volumetric removal of lens tissue can be preformed inconjunction with the various shot patterns provided for increasingaccommodative amplitude. In this manner both presbyopia and refractiveerror can be addressed by the same shot pattern and/or series of shotpatterns. The volumetric removal of lens tissue finds furtherapplication in enhancing corrective errors for patients that have hadprior corneal laser visions correction, such as LASIK, and/or who havecorneas that are too thin or weak to have laser corneal surgery.

In all of the laser shot patterns provided herein it is preferred thatthe laser shot patterns generally follow the shape of the lens andplacement of individual shots with respect to adjacent shots in thepattern are sufficiently close enough to each other, such that when thepattern is complete a sufficiently continuous layer and/or line and/orvolume of lens material has been removed; resulting in a structuralchange affecting accommodative amplitude and/or refractive error and/orthe removal of lens material from the capsule. Shot spacing of lesser orgreater distances are contemplated herein and including overlap asnecessary to obtain the desired results. Shot spacing considerationsinclude gas bubble dissipation, volume removal efficiency, sequencingefficiency, scanner performance, and cleaving efficiency among others.For example, by way of illustration, for a 5 μm size spot with an energysufficient to cause photodisruption, a spacing of 20 μm or greaterresults in individual gas bubbles, which are not coalesced and dissipatemore quickly, than with close shot spaces with the same energy, whichresult in gas bubble coalescence. As the shot spacing gets closertogether volume efficiency increases. As shot spacing gets closertogether bubble coalescence also increases. Further, there comes a pointwhere the shot spacing becomes so close that volume efficiencydramatically decreases. For example, by way of illustration, for a 450femtosecond pulse width and 2 microjoules energy and about a 5 μm spotsize with a 10 μm separation results in cleaving of transparent oculartissue. As used herein, the term cleaving means to substantiallyseparate the tissue. Moreover, the forgoing shot spacing considerationsare interrelated to a lesser or greater extent and one of skill in theart will know how to evaluate these conditions based upon the teachingsof the present disclosure to accomplish the objectives herein. Finally,it is contemplated that the placement of individual shots with respectto adjacent shots in the pattern may in general be such that they are asclose as possible, typically limited by the size and time frame ofphotodisruption physics, which would include among other things gasbubble expansion of the previous shot. As used herein, the time frame ofphotodisruptive physics referrers to the effects that take placesurrounding photodisruption, such as plasma formation and expansion,shock waive propagation, and gas bubble expansion and contraction. Thus,the timing of sequential pulses such that they are timed faster thansome of, elements of, or all of those effects, can increase volumetricremoval and/or cleaving efficiency. Accordingly, we propose using pulserepetition frequencies from 50 MHz to 5 GHz., which could beaccomplished by a laser with the following parameters: a mode lock laserof cavity length from 3 meters to 3 cm. Such high PRF lasers can moreeasily produce multiple pulses overlapping a location allowing for alower energy per pulse to achieve photodisruption.

The terms first, second, third, etc. as used herein are relative termsand must be viewed in the context in which they are used. They do notrelate to timing, unless specifically referred to as such. Thus, a firstcut may be made after a second cut. In general, it is preferred to firelaser shots in general from posterior points in the laser pattern toanterior points, to avoid and/or minimize the effect of the gas bubblesresulting from prior laser shots. However, because of the varied lasershot patterns that are provided herein, it is not a requirement that astrict posterior to anterior shot sequence be followed. Moreover, in thecase of cataracts it may be advantageous to shoot from anterior toposterior, because of the inability of the laser to penetratesubstantially beyond the cataract.

Without further elaboration, it is believed that one skilled in the artcan, using the preceding description, utilize the present invention toits fullest extent. The following specific embodiments are, therefore,provided as examples of the invention and should be construed as beingmerely illustrating and not limiting the scope of the invention or thedisclosure herein in any way whatsoever.

The following examples are based upon measured lens data and lens datathat is obtained by using Burd modeling, which model is set forth inBurd et al., Numerical modeling of the accommodating lens, VisionsResearch 42 (2002) 2235-2251. The Burd model provides the followingalgorithm for anterior and/or posterior shape:Z=aR ⁵ +bR ⁴ +cR ³ +dR ² +f

The coefficients for this algorithm are set forth in Table II.

TABLE II a b c d f Anterior (11-year) −0.00048433393427 0.00528772036011−0.01383693844808 −0.07352941176471 2.18 Posterior (11-year)0.00300182571400 −0.02576464843559 0.06916082660799 0.08928571428571−2.13 Anterior (29-year) −0.00153004454939 0.01191111565048−0.02032562095557 −0.07692307692308 2.04 Posterior (29-year)0.00375558685672 −0.03036516318799 0.06955483582257 0.09433962264151−2.09 Anterior (45-year) −0.00026524088453 0.00449862869630−0.01657250977510 −0.06578947368421 2.42 Posterior (45-year)0.00266482873720 −0.02666997217562 0.08467905191557 0.06172839506173−2.42

Additionally, the variables Z and R are defined by the drawing FIG. 9.

Thus, FIGS. 10, 11 and 12 provide cross sectional views of the lenshaving an outer surface 1001, 1101, 1201 for three ages, 18, 29 and45-year old respectively, based upon the Burd model and show growth insize along with shape changes with age. The units for the axes on thesedrawings, as well as for FIGS. 13 to 29 are in millimeters (mm).

EXAMPLE 1, provides for making nested, lens shaped shell cuts. The lasershot patterns are illustrated in FIG. 13, which provides the outersurface 1301 of a 45-year old lens based upon the Burd model. There isfurther provided a series of nested or essentially concentric shells andshell cuts, which essentially follow the shape of the lens. Thus, thereis provided a first shell cut 1302, a second shell cut 1304, and a thirdshell cut 1306. These shell cuts form a first shell 1303 and a secondshell 1305. Shells or partial shells are designed to increaseflexibility in the lens by decreasing the strength of nested fiberlayers by separating the bound layers, which it is theorized wouldreduce the structural strength and increase deflection for a given loador force. Thus, although not bound by this theory, it theorized thatincreasing the deflection of the lens for a given load or zonule forcewill increase the flexibility of the lens structure and, in turn, theamplitude of accommodation for that same zonule force. Thus, there areprovided a nested set of three layers, which essentially follows boththe anterior and posterior shapes. Moreover, it being readily understoodthat for this and the other examples that the shell cut is formed by andthus corresponds to a laser shot pattern.

Thus, the shell cuts in this example are positioned approximately suchthat the third shell cut 1306 is where 3 suture branches begin formingadditional branches, or approximately 6 mm lens equatorial diameter, atthe boundary of the fetal nucleus, or the lens at birth; the secondshell cut 1304 is where the 6 suture branch layer begins formingadditional branches at approximately 7.2 mm diameter, or the infantilenucleus or the lens at approximately age 3; and the first shell cut iswhere the 9 suture branch begins forming additional branches atapproximately 9 mm diameter, or at the adolescent nucleus atapproximately age 13.

EXAMPLE 2, provides as an alternative to using a 45-year old lens shapefrom the Burd model, the actual patient lens structural or shape datamay be utilized to customize surgery for each patient. As an example, a45-year old human cadaver lens, whose shape was measured optically andmathematically fit via the same fifth order function used in the Burdmodel, yields coefficients unique to the measured lens. The outercross-section shape of this lens and a shot pattern similar to that ofExample 1, but which was tailored to the particular lens of this Exampleis illustrated in FIG. 14. Thus, there is provided in this Figure anouter surface 1401 of the 45-year old lens. There is further provided aseries of nested or essentially concentric shells and shell cuts. Thus,there is provided a first shell cut 1402, a second shell cut 1404, and athird shell cut 1406. These shell cuts form a first shell 1403 and asecond shell 1405. It is further noted that any of the exemplary cutsand shot patterns can be implemented via partial or full shells and/orcan be implemented via modeled (the Burd model being just one example)or measured lens data.

EXAMPLE 3 provides a shot pattern for cutting partial shells on themeasured 45-year old lens, and having an excluded defined central zone.Thus, as illustrated in FIG. 15 there is provided an outer surface 1501of a 45-year old lens, a central zone 1512, partial cuts 1502, 1504,1506, 1507, 1509 and 1511. This also provided partial shells 1503, 1505,1508 and 1510. These partial cuts as shown are part of the samegenerally annularly shaped. Thus, cuts 1502 and 1507, cuts 1504 and1509, and cuts 1506 and 1511 are the opposite sides respectively ofthree generally annularly shaped partial.

EXAMPLE 4 provides a shot pattern for cutting partial shells on themeasured 45-year old lens and having both an excluded defined peripheralzone and central zone. Thus, as illustrated in FIG. 16, there isprovided an outer surface 1601 of a 45-year old lens, a central zone1622 and two peripheral zones 1620 and 1621. There is further providedpartial cuts 1602, 1604, 1605, 1606, 1607, 1611, 1613, 1615, 1617, and1618 as well as, partial shells 1603, 1608, 1609, 1610, 1612, 1614, 1616and 1619. As with example 3 and FIG. 15 these cuts are viewed in crosssection and thus it is understood that they are opposite sides ofgenerally annular ring shaped cuts, which essentially follow the shapeof the lens and which encompasses the central zone 1622. There are thus5 partial cuts depicted in FIG. 16.

EXAMPLE 5 provides a laser shot pattern for a finer detailed cutting ofthe lens to approximate the structural boundaries at 3, 4, 5, 6, 7, 8, 9suture branches, or the use of six shells. Thus, there is shown in FIG.17 seven essentially concentric shot patterns 1702-1708, which createseven corresponding shell cuts and which also create six correspondingshells 1709-1714. The outer surface 1701 of a 45-year old lens asmeasured is also provided in FIG. 17. While this example provides forthe creation of six shells, it is understood that the lens containsthousands of fiber layers and that it may be desirable to utilize muchgreater than six shells and up to hundreds or even thousands, dependingon the resolution of the laser deliver system and laser beam parameters.

Examples 6-12 relate to the volumetric removal of lens material in apredetermined shape, based upon a precise shot pattern. Thus, theseexamples illustrate how refractive change by shaped volumetric reductionmay be accomplished. This approach recognizes a limitation ofphotodissruption laser beam delivery, i.e., that the gas bubbles createdare considerably larger then the resultant material void found after allgas bubble dissipation occurs. This can have the effect of causingmaterial voids to be spaced further apart than ideal for high efficiencyvolume removal. Thus, it is recognized that the closest spacingattainable, depending on detailed laser spot size, energy and pulsewidth, may provide a low, net volumetric removal efficiency, which isthe ratio of achieved volume removal to the volume of material treated.A simple example considers a void size equal to the spacing betweenvoids yielding a nominal 50% linear efficiency, which from symmetricgeometry has a 25% area efficiency and a corresponding 12.5% volumetricefficiency of void creation. Thus, by way of example an approach isprovided whereby the treatment shaped volume is proportionally largerthan desired shaped volume removal to compensate for the low volumeefficiency. In other words, if a large shape change with low volumeremoval efficiency is attempted then a small shape change should beachieved. Other effects such as void shape, asymmetries, void location,tissue compliance as a function of age, external forces and more, mayeffect the final volume efficiency and experimental validation ofvolumetric efficiency may be required.

EXAMPLE 6 provides a shot pattern and volume removal to make a negativerefractive change, or reduce the power in the crystalline lens by 3Diopters, using the Gullstrand-LaGrand optical model, which wouldrequire the removal of approximately 180 um centrally tapering to 0 overa 3 mm radius. As illustrated in FIG. 18 there is provided an outer lenssurface 1801 and a shot pattern 1802 for the desired volume removal. Toachieve the full 3 Diopters refractive change directly, the shot patternwould have to remove essentially 100% of the shaded region volume whichis extremely difficult due to low volume efficiency found inphotodissruption laser beam delivery.

EXAMPLE 7, is based upon dealing with low volume removal efficiency andin this example the assumption that we have a volumetric efficiency of12.5% or ⅛^(th) we would treat an 8 times larger volume or 1.44 mm thickto compensate for the low volume efficiency, tapering to 0 over the same3 mm as shown in FIG. 19, which illustrates a lens outer surface 1901and a shot pattern 1902. As with the prior examples the shape of theshot pattern is based upon and essentially follows the shape of theouter surface 1901 Of the lens.

EXAMPLE 8 provides a shot pattern to cause a refractive change toincrease lens power or reduce hyperopia in patients, where the shotpattern is primarily implemented in the anterior region of the lens.This pattern is illustrated in FIG. 20, which provides an outer surface2001 and thus shape of the lens and a shot pattern 2002.

EXAMPLE 9 provides a shot pattern to cause a refractive change toincrease lens power or reduce hyperopia in patients, where the algorithmis primarily implemented in the posterior region of the lens. Thispattern is illustrated in FIG. 21, which provides an outer surface 2101and thus shape of the lens and a shot pattern 2102. This example furtherillustrates a shot pattern having a shape is modified to primarilyfollow the posterior curve of the lens.

EXAMPLE 10 provides a shot pattern to cause a refractive change toincrease lens power or reduce hyperopia in patients, where the shotpattern is primarily implemented in the central region of the lens.Thus, as illustrated in FIG. 22, there is provided an outer surface 2201of the lens and a shot pattern 2202, which provides a volumetric shape.It further being noted that the anterior shape of the lens or posteriorshape of the lens or both can be utilized to determine the shape of theshot pattern and/or volumetric shape.

EXAMPLE 11 provides two volumetric shot patterns that follow the shapeof the lens surface to which they are adjacent. Thus, as illustrated inFIG. 23, there is provided an outer surface 2301 and thus shape of thelens and a shot pattern having two volumetric shot patterns; a firstshot pattern 2302 positioned in the anterior region of the lens and asecond shot pattern 2303 positioned in the posterior region, whichpatterns provide a volumetric shape. Thus, the volumetric shapes to beremoved from the lens are located in the anterior and posterior regionsof the lens and have a surface that follows the anterior and posteriorshape of the lens respectively.

EXAMPLE 12 illustrates a manner in which different shot pattern featuresare combined to address both refractive errors and those to increaseflexibility utilizing a plurality of stacked partial shells, which arepartially overlapping. Thus, as illustrated in FIG. 24, there isprovided an outer surface 2401 and thus shape of the lens and there areprovided partial shell cuts 2402, whose extent is defined by arefractive shape, forming annular rings shaped partial shells 2403. Theplacement of the partial shell cuts are adjacent the anterior surface ofthe lens as shown it FIG. 24. The partial shell cuts may similarly beplaced adjacent the posterior surface of the lens, in which case theyshould follow the shape of that surface. Thus, by precisely followingthe individual shape of the layers within the lens more effectivecleaving is obtained.

The shot pattern in the figures associated with EXAMPLES 6,7,8,9,10 and11 are shown to cut horizontal partial planes whose extent is defined bya refractive shape. It is to be understood that as an alternative tohorizontal planes, vertical partial planes or other orientation cutswhose extent is defined by the refractive shape may be used.

Examples 13 and 14 are directed towards methods and shot patterns fortreating and removal of cataracts and/or for clear lens extractions.Thus, there is provided a method for the structural modification of thelens material to make it easier to remove while potentially increasingthe safety of the procedure by eliminating the high frequency ultrasonicenergy used in Phaco emulsification today. In general, the use ofphotodissruption cutting in a specific shape patterns is utilized tocarve up the lens material into tiny cube like structures small enoughto be aspirated away with 1 to 2 mm sized aspiration needles.

EXAMPLE 13 provides a shot pattern to create 0.5 mm sized cubes out ofthe lens material following the structural shape of a 45-year old BurdModel lens. It is preferred that the patient's actual lens shape can bemeasured and used. Thus, as illustrated in FIG. 25, there is provided anouter surface 2501 and thus an outer shape of the lens. There is furtherprovided a shot pattern 2502 that creates grid like cuts, the end ofwhich cuts 2503 essentially follows the shape of the lens. There isfurther provided one shell cut 2504, which is integral with the gridlike cuts. The sequence of laser shots in the pattern in FIG. 25 may beexecuted from posterior to anterior, as in most of the patternsdisclosed herein, to obtain more predictable results by reducing thevariation caused by shooting through gas bubbles. However, it may bedesirable to shoot cataracts from the anterior to the posterior for thepurpose of choosing the lesser of two undesirable effects. Thus, it maybe advantageous to shoot through the gas bubbles, or let them dissipate,rather then shooting through cataractus tissue, which much more severelyscatters the light and more quickly prevents photodissruption comparedto gas bubble interference. Accordingly, it is proposed to photodissruptthe most anterior sections of the cataract first, then moveposteriorally, shooting through gas bubble remnants of cataractoustissue, to the next layer of cataract tissue below. In addition toshooting the laser in anterior z planes then moving posterior, it isfurther provided to essentially drill down anterior to posterior, whichwe call the z axis throughout this document and then move in x/y anddrill down again.

EXAMPLE 14 provides for a clear lens extraction. In this example theshot pattern of FIG. 25 is applied to a clear lens and that lensmaterial is subsequently removed. In this example shooting fromposterior to anterior is desirable.

EXAMPLE 15 provides for a precision capsulorhexis. The creation ofprecise capsulorhexis for the surgeon to access the lens to remove thelens material is provided. As illustrated in FIGS. 30A-D, there isprovided an outer surface 3001 and thus an outer shape of the lens.There is further provided a ring shaped band shape cut 3002 and shotpattern. Thus, the figure shows the cross section view of this ringshaped annular band and accordingly provides for two sides 3002 of thering. The ring shaped capsulorhexis cuts of 100 μm deep, approximatelycentered on the anterior lens capsule surface and precisely 5 mm indiameter. Since the lens capsule is approximately 5 to 15 μm thick, itis desirable for the depth of the cut to be typically between 5 andseveral hundred um, although there is not much penalty for cuttingseveral millimeters. This diameter, however, can be varied between 0.1mm to 9 mm diameter and the capsulorhexis can be elliptical with the xaxis different then the y axis or other shapes. A particular IOL maybenefit from and/or may require a particular capsulorhexis shape.

Examples 16 to 17 relate to gradient index modification of the lens.Moffat, Atchison and Pope, Vision Research 42 (2002) 1683-1693, showedthat the natural crystalline lens contains a gradient index ofrefraction behavior that follows the lens shells structure anddramatically contributes to overall lens power. They also showed thatthis gradient substantially diminishes, or flattens as the lens agesreducing the optical power of the lens. The loss of gradient index withage most likely explains the so-called Lens Paradox, which presents theconundrum that the ageing lens is known to grow to a steeper curvatureshape that should result in higher power, yet the aging lens has similarpower to the youthful lens. Essentially it is postulated that theincrease in power due to shape changes is offset by the power loss fromgradient index loss. Examples of the youthful vs old age gradient indexbehavior is shown in FIG. 31, which provides data taken from the morerecent work from the same group Jones, Atchison, Meder and Pope, VisionResearch 45 (2005) 2352-236. We can see from this figure that the oldlens 3101 has a flat index behavior radially 3102 and the young lens3103 has continuously diminishing index radially 3104 from approximately1.42 in the center to 1.38 nearer the outer shells of the lens. Thus,based upon this data it is provided to use the photodissruptive laser inthe creation of small voids within the lens fiber material which willthen fill-in with aqueous humor fluid which has a lower index ofrefraction and, via area weighting or volume weighting, decrease the netrefractive index of a particular region. Accordingly, if different voiddensities are placed in nested shell volumes, then this would diminishthe average index of refraction of essentially concentric regions in asimilar manner to the youthful lens.

EXAMPLE 16 provides a gradient index modification, which has differentvoid densities placed in nested volumes, as shown in FIG. 26. Thus,there is provided a series of nested shot patterns 2602 and a lens outersurface 2601, with each pattern creating an incrementally different voiddensity in the lens material. For example, if a nominal 25% weightingefficiency was obtained in the most densely treated region, filling thatvolume with 1.38 index of aqueous humor, and the remaining region thatwas 75% lens material of index 1.42, then the average resultant index ofrefraction would be 0.25*1.38 +0.75*1.42 or 1.41, which we see from FIG.31, that would restore the gradient from the center to a 2 mm radius,which is most central optical region for visual function. Thus, FIG. 26shows a distributed regional treatment of increasing density from thecenter of the lens to the periphery of the lens.

EXAMPLE 17 provides a gradient index modification that is similar toexample 16, except that the area where void density is changed islocated further from the outer surface of the lens. This example andpattern is illustrated in FIG. 27. Thus there is provided a series ofnested shot patterns 2702 and lens outer surface 2701, with each patterncreating an incrementally different void density in the lens material.Moreover, this figure shows a distributed regional shell treatment thatis primarily confined to the nucleus.

EXAMPLE 18 provides for the cutting in relation to suture lines. Thus,cuts along either modeled suture lines, according to Kuzak describedsuture locations as a function of shell geometry with age and shape, ormeasured suture lines may be used. The latter being provided by themeasuring of patient lens sutures with a CCD camera and aligning suturecuts to the measured locations of suture lines. Thus, the brightestsuture lines and or those with the widest spatial distribution likelybelong to the deepest layers, and perhaps the initial Y suture branchesfound in the fetal nucleus. Further, there it is provided to cut Ysuture shapes at the lowest layers in the lens and then increasing thenumber of cuts as the layers move out peripherally. Thus, according tothese teachings, FIGS. 28 & 29 shows three different cutting patterns2801, 2802, 2803 in the anterior portion of the lens that can be doneseparately or in combination. Thus, FIGS. 28A, C & E shows x-y cuts2801, 2802, 2803 looking down at the anterior side of the lens. FIGS.28B, D, and F are schematic representation to illustrate that the starshaped patterns follow the shape of the layer of the lens and do notshow the actual cut. FIG. 29 is the combination of the illustrations inFIGS. 28B, D, and F to show their relative positions. It is understoodthat similar suture cuts can be made in the posterior following theposterior shell curves there, based again on either modeled geometry ormeasured lens data. There is yet further provided cutting3,4,5,6,7,8,9,10,11,12,13,14 and 15 branch sutures per Kuszak., cutseparately or in any combination.

The components and their association to one another for systems that canperform, in whole or in part, these examples are set forth above indetail. Additionally, it is noted that the functions of the methods andsystems disclosed herein may be performed by a single device or byseveral devices in association with each other. Accordingly, based uponthese teachings a system for performing these examples, or parts ofthese examples, may include by way of illustration and withoutlimitation a laser, an optical system for delivering the laser beam, ascanner, a camera, an illumination source, and an applanator which hasreference marks thereon. These components are positioned so that whenthe eye is illuminated by the illumination source, light will travelfrom the eye through the applanator to the scanner. In this system theillumination source is movable with respect to the eye to providevarying angles by which the eye can be illuminated.

Similarly, such system may also include by way of example and withoutlimitation a laser, a system for determining the position and shape ofcomponents of an eye, a camera, a controller (which term refers to andincludes without limitation processors, microprocessors and/or othersuch types of computing devices that are known to those of skill in theart to have the capabilities necessary to operate such a system), anillumination source, and an eye interface device. In this system thescanner is optically associated with the eye interface device, such thatwhen the eye is illuminated by the illumination source, light willtravel from the eye through the eye interface device to the scanner. Thescanner is further optically associated with the camera, such that thescanner has the capability to provide stereo pairs of images of the eyeto the camera. The camera is associated with the controller and iscapable of providing digital images of the eye to the controller; and,the controller further has the capability to determine, based in partupon the digital images provided from the camera, the shape, positionand orientation of components of the eye.

Moreover, such systems may also include by way of example and withoutlimitation a system for delivering a laser to an eye. This system wouldhave a laser, a scanner, a camera, an illumination source, an eyeinterface device, a means for determining the shape and position ofcomponents within an eye and a means for directing the delivery of alaser beam from the laser to a precise three dimensional coordinate withrespect to the components of the eye, the means for directing thedelivery of the laser beam having the capability to direct the beambased at least in part on the determination of the shape and position ofcomponents within the eye by the determining means.

From the foregoing description, one skilled in the art can readilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand/or modifications of the invention to adapt it to various usages andconditions.

What is claimed:
 1. A method for delivering a laser beam to a lens of aneye comprising: a. providing a laser beam from a laser in a laserdelivery system; b. the laser delivery system defining an optical path,whereby the laser delivery system directs the laser beam along theoptical path from the laser to the lens of the eye; wherein componentsare located in the optical path, the components comprising: an x yscanner; a z focus mechanism; and, a reference; wherein the reference isconfigured for use in making a laser lens positional determination; c.the laser delivery system determining the shape and position of the lenswith respect to the laser: (i) based upon the reference and (ii) basedupon mathematical modeling and observation data; and, d. the laserdelivery system automatically focusing the laser beam to a location inthe lens of the eye; wherein the location is selected based upon thedeterminations of step c.
 2. The method of claim 1, wherein thereference is a reference mark and is located on a patient interfacedevice.
 3. The method of claim 1, comprising directing the laser beam inthe lens of the eye in a predetermined shot pattern; the lens defining ashape; the shot pattern comprising a series of shots that form avolumetric shaped removal, the volumetric shaped removal beingpositioned entirely within the lens and essentially following the shapeof the lens.
 4. The method of claim 1, comprising the step of directingthe laser beam in a shot pattern to from an annular ring shapedcapsulorhexis.
 5. The method of claim 4, comprising: directing the laserbeam in the lens of the eye in a predetermined shot pattern, the shotpattern comprising a series of shots that form a grid cut pattern:removing the lens material; and, replacing the lens material.
 6. Amethod for delivering a laser beam to a lens of an eye comprising: a.providing a laser beam from a laser in a laser delivery system; thelaser delivery system further comprising a lens model and a controlsystem; b. providing to the laser delivery system observation data of aposition of the lens with respect to the laser system; the laserdelivery system determining the position and shape of a structure of thelens based on the lens model and the observed data; c. the laserdelivery system automatically directing the laser beam in the lens ofthe eye in a pattern of shots; d. wherein the pattern of shots is basedupon the determined position and shape of the structure of the lens; e.the laser delivery system automatically focusing a shot of the shotpattern in the lens of the eye based upon the determination of step b.7. The method of claim 6, comprising directing the laser beam in thelens of the eye in a predetermined shot pattern, the shot patterncomprising as series of shots that form a volumetric shaped removal, thevolumetric shaped removal being positioned entirely within the lens andessentially following a shape of the lens.
 8. The method of claim 6,comprising directing the laser beam in a shot pattern to form an annularring shaped capsulorhexis.
 9. A method for delivering a laser beam to alens of an eye comprising: a. determining a position of the lens of theeye with respect to a fixed reference in a laser beam delivery system;and determining a shape and the position of an outer surface of the lensof the eye based upon modeling data and observation data, wherein thelaser beam delivery system is configured to deliver a laser beam alongan optical path from a laser to the lens of the eye; wherein componentsare located along the optical path, the components comprising: an x yscanner; a z focus mechanism; and the fixed reference; b. the laser beamdelivery system directing the laser beam to the lens of the eye alongthe optical path; c. the laser beam delivery system automaticallydirecting the laser beam in the lens of the eye in a predetermined shotpattern, the shot pattern comprising as series of shots that form avolumetric shape; and, d. the volumetric shape being positioned at alocation entirely within the lens of the eye; wherein the locationwithin the lens of the eye is based upon the determined position andshape of the outer surface of the lens of the eye.
 10. A method ofdirecting a laser beam to the lens of the eye comprising: a. providingobserved lens data to a laser beam delivery system; the laser beamdelivery system comprising: (i) optical path components defining anoptical path; (ii) wherein the optical path components comprise an x yscanner, a z focus, and a fixed reference; and, (iii) modeled lens data;b. based upon the modeled lens data, the fixed reference, and theobserved lens data the laser beam delivery system determining a shapeand a position of the lens, wherein the observed data is obtained from alight source; and, c. the laser beam delivery system directing a laserbeam to the lens of the eye in a laser beam pattern, based upon thedetermined shape and the determined position of the lens, wherein thelaser beam is directed along the optical path.